The present invention relates to an inverted portal axle configuration, and more particularly to a lubrication system therefore.
Mass transit vehicles, such as trolley cars, buses, and the like typically have seats aligned at the lateral sides of the vehicle, with a central aisle and floor extending along the vehicle. In order to facilitate entering and exiting from the vehicle, it is desirable to have the vehicle floor and aisle positioned relatively low to the ground. This provides faster cycle time at bus stops.
Many such vehicles provide a rigid axle having a gear box at each longitudinal end to form an inverted portal axle configuration. The inverted portal axle configuration is particularly effective in providing a low floor vehicle.
Disadvantageously, the inverted portal axle configuration requires a relatively large volume of lubricant within the axle. The large volume of lubricant requires the rotating shaft within the rigid axle to be almost completely immersed to provide an adequate lubricant level within the wheel end. Such a relatively large volume of lubricant adds significantly to the axle weight. In some instances, vehicle operation may force lubricant out of the wheel ends and into the axle which may result in spinout damage to the wheel end gear train.
Accordingly, it is desirable to provide an inverted portal axle configuration which assures a proper quantity of oil in both the wheel ends and the axle, while reducing the total quantity of oil and maintain a low floor profile to improve vehicle access.